Orthodontic brackets are appliances used in treatment programs to correct the alignment of improperly positioned teeth. Brackets are small slotted bodies, typically shaped to mate with the natural contour of the associated teeth, and slotted to receive an arch wire which delivers corrective force urging each malpositioned tooth toward proper alignment.
Secure attachment of brackets to teeth is accomplished in several ways. Traditionally, brackets have been made of metal, and welded to metal tooth bands contoured to fit snugly over the teeth for cemented attachment. This banded attachment continues to be widely used for back (molar) teeth where maximum bracket and attachment strength is desired, and the bands and brackets are not visible when the patient smiles.
A development of the last several decades is direct cemented attachment of a bracket to the tooth surface, and without use of a tooth band. Cemented or direct-bond brackets of this type have come into widespread use because elimination of the bands minimizes the size of the visible appliances on the teeth, and presents a more pleasing appearance when smiling.
Direct-bond brackets have been made of both metal and plastic but a recent advance is the construction of brackets from ceramic materials. Ceramic brackets are strong, and can be made almost invisible against the tooth surface by proper choice of materials. Bonding adhesives for ceramic brackets have become available, and provide a secure bracket attachment to the associated tooth. Ceramic brackets, however, are hard and brittle, and are more difficult to remove or debond from the teeth at the end of the treatment phase which requires brackets.
Bracket debonding involves breaking or fracturing the adhesive interface between tooth and bracket base to enable bracket removal, followed by cleaning of the tooth surface to remove any residual adhesive. Debonding of metal or plastic brackets (which are relatively ductile as compared to ceramic brackets) is usually done by breaking or shearing the adhesive bond with a plier-like debonding tool with chisel-like tips which peel the bracket away from the tooth.
Conventional debonding pliers and techniques have been found unsatisfactory for removal of ceramic brackets for several reasons. First, the high bond strength of the adhesive interface tends to resist conventional linear peeling forces. Second, the brittleness of ceramic brackets leads to bracket fracture and difficult removal with conventional debonding tools, especially when debonding force is applied to bracket tie wings which are structurally weaker than the main bracket body.
We have found that debonding of ceramic brackets is safely and effectively achieved by applying a quick rotary or twisting force to the bracket with a special tool designed to clasp the mesial and distal side surfaces of the bracket. This method and tool produce good fracturing of the adhesive bond with minimum risk of bracket breakage, and with no greater patient discomfort than experienced when removing a direct-bond metal or plastic bracket with a conventional debonding plier.